The present invention relates to computer systems and more particularly to monitoring processor temperature to trigger clock or voltage throttling in the event of processor overheating.
Computer systems, from small handheld electronic accessories to mediumsized mobile and desktop systems to large servers and workstations, are becoming increasingly pervasive in our society. Computer systems typically include one or more processors. A processor manipulates and controls the flow of data in a computer by executing instructions. To provide more powerful computer systems for consumers, processor designers strive to continually increase the operating speed of the processor. As processor speed increases, the power consumed by the processor tends to increase as well. This increase in power consumption typically causes the processor to run hotter. Unfortunately, if the processor overheats, it may be rendered permanently unreliable or inoperable.
To prevent overheating of the processor, also referred to as xe2x80x9covertempxe2x80x9d, processor and computer system designers build overtemp prevention mechanisms into their computers. These mechanisms typically include a thermal sensor, such as a thermally sensitive diode or thermocouple, placed on or near the processor package to monitor the temperature of the processor. A threshold temperature is established by the designer, and if the temperature measured by the thermal sensor exceeds this threshold, the processor is placed into a low power mode (or power throttled) until it cools off.
One challenge facing processor and system designers is determining where to position the thermal sensor. Depending on the system configuration, proper placement of the thermal sensor may be difficult. The thermal sensor should be placed close enough to the processor to obtain a rapid, accurate temperature reading and in a manner that does not interfere with the thermal dissipation system. If the thermal sensor is not sufficiently thermally coupled to the processor, a processor overtemp may go undetected by the system, resulting in damage to the processor. To prevent this, designers may simply increase the overtemp threshold guardband, but this may reduce processor efficiency by unnecessarily throttling a processor that may not be in a true overtemp situation.
The present invention addresses this and other problems associated with the prior art.
A processor comprises a processing core integrated on the same chip with a temperature sensing diode. The two terminals of the diode are coupled to each of two I-O ports of the processor. In accordance with one embodiment of the present invention, the electrical characteristics across the I-O ports are measured by an external control circuit to calculate a temperature of the processor. This temperature is compared to a threshold, and either an overtemp or undertemp signal is transmitted via a control line.
Other features and advantages of the present invention will be apparent from the accompanying figures and the detailed description that follows.